Lecture Test 2 Part One Flashcards
What is hemotology?
the study of blood
Blood is a type of
connective tissue
what are the functions of blood?
transportation
prevention/protection
temperature regulation
Blood transports oxygen
from the lungs into the cells
Blood transports carbon dioxide
from the cells to the lungs
Blood transports nutrients from
the GI tract
Blood transports hormones from
the endocrine glands
How does blood prevent/protect?
it prevents infection and blood loss
How does blood maintain temperature?
it moves blood to the surface when hot and brings blood to the core when cold
In a human adult there is _______ amount of blood in the body
4-6 L
what is the pH of blood?
7.35-7.45
Blood is composed of
plasma and formed elements
what are formed elements?
RBCs
WBCs
Platelets
What is plasma?
the fluid portion of blood
Plasma is _____ of whole blood
55%
What is plasma made of?
water electrolytes wastes nutrients proteins respiratory gases
what proteins are found in plasma?
albumin
globulin
fibrinogen (clotting factor)
what color is plasma?
straw colored
what is serum?
plasma minus the clotting factors
red blood cells are called
erythrocytes
white blood cells are called
leukocytes
platelets are called
thrombocytes
what is hematocrit?
measurements of RBCs in the blood
what is a normal hematocrit level at sea level?
40%
What is hempoiesis?
Process of forming new blood cells
Within the red bone marrow there are stem cells called
hemocytoblasts which give rise to RBCs, WBCs and Platelets
Hemopoiesis in the fetus occurs in
yolk sac, liver, spleen, thymus
Hemopoiesis in a young child occurs in
red bone marrow of all bones
Hemopiesis in an adult occurs in
red bone marrow of select bones
Erythrocytes are shaped as
a bi-concave disc
Erythrocytes have no
nuclei
The absence of a nucleus allows erythrocytes to
have more room for hemoglobin
what is hemoglobin?
an oxygen carrying pigment
A hemoglobin molecule is composed of
4 polypeptide chains with a HEME structure in the midst of each polypeptide chain.
Each HEME contains
an iron that will be able to combine with oxygen
Each hemoglobin molecule can carry
4 oxygens
What is the function of the biconcave disc of RBCs?
it increases surface area for gas diffusion and gives the cell more flexibility to fit through small vessels
Since there is no nucleus, no _______ can occur
repair
what is erythropoiesis?
process of RBC production
erythropoiesis starts as a
hemocytoblast
what is the pathway for erythropoiesis?
hemocytoblast
reticulocyte
erythrocyte
how long does it take to make RBCs?
1-2 days
hemocytoblasts are found in
red bone marrow
reticulocytes and erythrocytes are found in
circulating blood
what is regenerative anemia?
5% reticulocyte count. Bone marrow working. Takes 3-4 days to determine
what is nonregenerative anemia?
0-1.5% reticulocyte count. Bone marrow is not working
The number of erythrocytes in the blood must be kept
constant
The body maintains RBCs in the blood by
erythropoietin
what is erythropoietin?
hormone that is released by the kidneys that will stimulate the red bone marrow to increase production of RBCs
what is the stimulus for erythropoietin?
hypoxia
what is hypoxia?
lack of adequate oxygen
renal failure patients may lack erythropoietin and therefore
suffer a low hematocrit, often half of the normal level
what is administered to renal failure patients?
recombinant erythropoietin
Males have a higher hematocrit due to
testosterone
what is testosterone?
a male hormone that stimulates the production of RBCs
what are the effects of living in the mountains?
Higher amounts of RBCs are produced. Hematocrit will be higher
what are the effects of visiting the mountains?
erythropoietin is released and RBCs are produced three days later. When you go home on the fourth day, you will have more RBCs and more oxygen in the blood
RBCs live for
120 days
Why do the RBCs die?
the lack of a nucleus and the inability to produce new proteins.
what happens to RBCs that are removed from circulation and destroyed?
Macrophages in the liver, spleen, and other tissues phagocytize them
when hemoglobin is broken down, iron and polypeptides
are recycled
when hemoglobin is broken down, heme is
converted to biliverdin
When hemoglobin is broken down, biliverdin is
converted into bilirubin
when hemoglobin is broken down, bilirubin is
picked up by hepatocytes, glucaronic acid is added and eventually becomes bile
when hemoglobin is broken down, bile is
converted to urobilinogen in the intestines (some will go to the kidneys)
when hemoglobin is broken down, urobilinogen becomes
stercobilin in the digestive tract
what is icterus/jaundice?
bilirubin is present in the blood
what is responsible for the color of urine?
urobilinogen being processed by the kidneys
what is responsible for the color of feces?
stercobilin being eliminated
what is anemia?
reduced oxygen-carrying ability in the blood due to a decreased hemoglobin level
what are the symptoms of anemia?
fatigue, pale, cold
what are the three main causes of anemia?
not making RBCs
destroying RBCs
Losing RBCs
what is hemorrhagic anemia?
blood loss leading to a decreased amount of RBCs in the blood
hemorrhagic anemia is an example of
losing RBCs
what is hemolytic anemia?
RBCs rupture prematurely leading to a decreased amount of RBCs in the blood.
What causes hemolytic anemia?
parasites or a transfusion of mismatched blood
what is hemolytic anemia an example of?
RBCs being destroyed
what is aplastic anemia?
pathology of the red bone marrow leading to low rbc count or malformed rbcs.
what causes aplastic anemia?
cancer, radiation, drugs
what is aplastic anemia an example of?
RBCs not being made
what is dietary anemia?
not enough iron in the blood to carry enough oxygen. Oxygen is needed for production of hemoglobin
what is dietary anemia an example of?
RBCs are not being made
who is most at risk for dietary anemia?
pregnant women
what is pernicious anemia?
a lack of intrinsic factor in the stomach.
Intrinsic factor is needed for
B12 absorption.
what is the treatment for pernicious anemia?
B12 injections
pernicious anemia is an example of
RBCs not being made
what is sickle cell anemia?
genetic disease in which the RBC looses its round shape and sickles. This leads to less oxygen going to the tissues and pain
sickle cell anemia is an example of
RBCs being destroyed.
what is polycythemia?
abnormal increase of RBCs that increases the viscosity of blood which slows down the flow and eventually decreases the rate of oxygen traveling to the tissues.
why would polycythemia occur?
chronic hypoxia as seen in patients with emphysema
what is primary polycythemia?
more erythrocytes and the same amount of fluid. Blood becomes thicker
what is secondary polycythemia?
same amount of erythrocytes but less fluid.
What usually causes secondary polycythemia?
dehydration
what is blood doping?
After visiting the mountains, blood is drawn and stored. RBCs are then transfused into the person right before a competition.
What is another banned practice in sports?
the use of recombinant erythropoietin.
Unlike erythrocytes, leukocytes are
nucleated cells that do not contain hemoglobin
What are leukocytes important in?
defense of the body against invaders
where are leukocytes formed?
red bone marrow
leukocytes are formed from
hemocytoblasts
What are the two types of leukocytes?
granular and agranular
what are granular WBCs?
cells that have one lobed nucleus within them and have granules in the cytoplasm.
What are the different types of granular WBCs?
neutrophils
eosinophils
basophils
What are agranular WBCs?
they do not have granules in the cytoplasm and their nuclei are large but not lobed.
what are the different typed os agraulocytes?
lymphocytes
monocytes
what color is a neutrophil?
colorless
what color is a basophil?
blue
what color is a eosinophil?
red
what is the pathway for granulocytes?
hemocytoblasts–>myloblasts–>neutrophils, eosinophil or basophil
what is the pathway for monocytes?
hemocytoblasts–>monoblast–>monocyte–>macrophage
what is the pathway for lymphocytes?
hemocytoblasts–>lymphoblast–>lymphocyte
How long do leukocytes live?
a few days except for lymphocytes that can live for months or years
The number of WBCs will increase when
there is an infection
When there is an infection ________ will occur
leukocytosis
What is diapedisis?
The movement of WBCs from the blood to infected tissues
How does diapedisis occur?
WBCs slow down, roll over the endotrhelial cells and then squeeze between the cells of the capillaries out of the vessel.
what is chemotaxis?
attraction of phagocytes to microbes by chemical stimulus
What is the first leukocyte to respond to an infection?
neutrophils
What do neutrophils do?
destroys the pathogen by phagocytosis
The second leokocyte to arrive at the scene of infection is the
monocytes.
What do monocytes do?
enlarge and differentiate into macrophages. They then phagocytize the invaders and clean up debris of dead cells after the infection is over.
What is the function of neutrophils?
phagocytosis
where are neutrophils made?
red bone marrow
where are eosinophils made?
red bone marrow
what is the function of eosinophils?
allergies and parasites
where are basophils made?
red bone marrow
what is the function of basophils?
release of histamine and heparin
where are lymphocytes made?
red bone marrow and lymph nodes
what is the function of lymphocytes?
making antibodies
where are monocytes made?
red bone marrow and lymph nodes
what is the function of monocytes?.
phagocytosis
what is the order of the leukocytes from most to least?
neutrophils lymphocytes monocytes eosinophils basophils
what does cytosis mean?
increased number of
what does penia mean?
decreased number of
what does philia mean?
increased number of
what is infectious mononucleosis?
contagious disease caused by the Epstein-Barr virus. Infects lymphocytes leading to an immune response
what are the symptoms of mononucleosis?
fever, swollen lymph nodes. Similar to strep throat
what is leukemia?
uncontrollable production of WBCs. So many abnormal WBCs are produced that not enough RBCs and platelets can form.
What follows leukemia?
anemia and clotting difficulties
what is the treatment for leukemia?
radiation, chemotherapy, bone marrow transplants, umbilical cord blood transplantation
what are thrombocytes?
fragments of megakaryocytes that will be released into the blood.
Do thrombocytes have a nucleus?
no
How long to thrombocytes live?
5-10 days
megakaryocytes are derived from
hemocytoblasts
what is the function of platelets?
preventing blood loss
what is hemostasis?
stoppage of bleeding
what are the 3 phases of hemostasis?
vascular spasms
platelet plug
coagulation
what are vascular spasms?
vasoconstriction locally.
Vasoconstriction of the injured vessel
decreases the amount of blood lost.
How long does vasoconstriction occur?
minutes to a few hours
what is platelet plug formation?
temporary plug made of platelets
How long does it take for the platelet plug to form?
1-2 minutes
what causes the platelets to stick to the injured site?
platelets swell and their membranes change and become sticky
what are the three stages of platelet plug formation?
platelet adhesion
platelet activation
platelet aggregation
what is platelet adhesion?
a break in the endothelium leads to thrombocytes adhering to the collagen. Von Willebrand factor is released by damaged endothelial cells and thrombocytes are tacked down
what is platelet activation?
prostaglandin is released by thrombocytes and it acts as a chemotaxis for more thrombocytes
what is platelet aggregation?
new platelets are attached to existing platelets by fibrinogen
During coagulation, what is formed?
a clot
what are procoagulants?
substances that enhance the clot formation. Called clotting factors. Circulate in inactive form
what are anticoagulants?
substances that inhibit the formation of a clot. Have both endogenous and exogenous anticoagulants.
what are some examples of endogenous anticoagulants?
heparin
antithrombin
what are some examples of some exogenous anticoagulants?
Coumadin
warfarin
heparin
EDTA
what is Coumadin?
given after a heart attack or stroke
what is warfarin?
rat posison
what is EDTA?
anticoagulant put in test tubes for blood draw
What is the coagulation pathway?
Begins with factor three in the extrinsic pathway and factor 12 in the intrinsic pathway. Along with calcium, they meet in the common pathway and form factor ten. Factor ten releases prothrombinase which conforms prothrombon into thrombin. Thrombin then conforms fibrinogen into fibrin
Fibrin strands then:
glue the platelets together and make the basis of the clot.
The web-like structure will trap formed elements inside of it and clot formation is normally completed
within 3-6 minutes after damage to the vessel
what is retraction?
the clot contracts and this brings the ruptured edges of the vessels closer together.
What does fibrinolysis do?
removes the unneeded clot when healing occurs.
fibrinolysis begins within
2 days and continues over several days until the clot is dissolved
In order for the clot to be dissolved, ________ needs to be activatedq
plasminogen
what is plasminogen?
an inactive blood protein
what activates plasminogen?
tissue plasminogen activator (t-pa)
what is the activated form of plasminogen?
plasmin
what is plasmin?
an active enzyme
In an emergency situation when a person has formed an abnormal clot that is blocking circulation as in a heart attack,
t-pa or streptokinase can be injected into the blood or introduced at the clot site
Does aspirin work as an anticoagulant or activator of plasminogen?
anticoagulant.
what is hemophilia?
hereditary deficiencies in clotting factors. Causes spontaneous bleeding
Who is mostly affected by hemophilia?
males
What is the treatment for hemophilia?
regular blood transfusions or injections of clotting factors
what is vitamin k deficiency?
Vitamin K is needed to produce four of the factors in the clotting process
what is impaired liver function?
unable to synthesize the procoagulants, even if vitamin K is present
who is mostly affected by impaired liver function
those with cirrhosis and hepatitis
what is thrombocytopenia?
number of platelets is reduced leading to spontaneous bleeding
what causes thrombocytopenia?
bone marrow malignancy, radiation and medication
what is DIC?
disseminated intravascular coagulation
what are the causes of disseminated intravascular coagulation?
heat stroke, septicemia, pregnancy
what is thrombosis?
a clot that develops and persists on a wall of an unbroken vessel
what si a thrombus?
the actual clot
If the thrombus is large enough,
it may block circulation causing death of tissue
what is coronary thrombosis?
blockage occurring in small vessels of the heart
what does coronary thrombosis lead to?
myocardial infarction
what is an embolus?
a thrombus that breaks away from the vessel wall and floats freely in the blood
what are the two most common places for a thrombus?
legs and the heart
what is the treatment for a myocardial infarction?
low dose aspirin
oxygen
t-pa
nitroglycerin
what does aspirin do?
prevents platelet plug from forming
what is a transfusion?
transfer of blood or blood components from one individual to another
what is an infusion?
introduction of a fluid other than blood such as saline
The surface of RBCs contain genetically determined glycolipids called
antigens
what is the ABO system?
system of grouping blood according to the presence or absence of antigen A and antigen B
